MAXDRILL ROCK DRILLING TOOLS: --Integral drill rod (HEX.19MM, HEX.22MM) , Plug drill rod (shank hex19mm hex.22mm) --Taper drill rod(hex.19mm, ... Drifting and tunneling tools : thread : R25, R28,R32 ,R35 ,tunnling drill rod (HEX.25MM, HEX.28MM, HEX,32MM, HEX,35MM) AND ... bit, button bit , asynmetrical button bit and etc) -Taphole drill rod and accessories We serve customized design, production and serive ...